Such a device is known, for example, from U.S. Pat. No. 4,912,718, the disclosure of which is incorporated herein by reference. In this case, the space is well utilized in terms of design, since the concept of using modules has been adopted to a very great extent.
The object of the invention is to provide on an even smaller surface a laser device with which the surface utilization can be improved, for example, by a factor or two. According to, for example, FIG. 5 of the U.S. Patent, there are two laser beam paths 14, 14'. The laser paths are arranged in a square. It is also possible to see, in the U.S. Patent, a series of continuous flanges 26, 31, 33, 36, 26', 31', 33', 36'. Intermediate corner flanges 16, 18, 16', 17', 18' are also visible. There is also an end flange 21. In said patent the carrying structure is, in the illustrative embodiment, a table 12. In this case, the flanges are arranged on the carrying structure. It is also possible to see inlet and outlet lines 66, 84, 87, 79, 88, 81, 89 arranged in a star configuration.
According to a further modification shown in FIG. 11 of the U.S. Patent two structural laser units are arranged on two levels, one in a head-down position disposed on top of the other. Since each of the units comprises at least one laser module or a plurality of modules and since each module comprises its own carrying structure, such doubling of modules means significant expenditure in material and costs, as well as on room. Furthermore, the dimensions of each individual carrying structure may vary under the influence of temperature changes quite differently from the other so that the effective length of the individual laser beam paths may change in different amounts. As a result, it is difficult to stabilize the effective resonant length especially when such beam paths have to be serially coupled.
The object according to the invention is achieved in a CO.sub.2 laser having the following features:
The longitudinal-flow CO.sub.2 laser, has a first and second laser beam path, each beam path having intermediate corner flanges with deflecting mirrors for folding the beam path in at least three partial segments. Each beam path is associated with a respective first and second geometric central plane zone. The CO.sub.2 laser has one end flange with a totally reflecting mirror and an output mirror and a carrying structure for supporting the flanges. The carrying structure is associated with a third geometric central plane zone disposed between the first and second plane zones and parallel thereto, so that the carrying structure is common to the flanges of the first and second laser beam path.
Because of the common carrying structure, both beam paths change their lengths equally as far as such change may occur. Also, because of the position of the carrying structure between both beam paths differences in heat properties of the beam paths are well balanced. And in that one carrying structure supports two beam path elements (flanges with inlet and outlet lines for gas circulation) the complete construction is more compact and saves material and weight.